Method of forming a germanium oxynitride film

ABSTRACT

A method for forming layers suitable for a V-NAND stack is disclosed. Specifically, the method may include multiple cycles for forming an oxide and a nitride in order to form an oxynitride layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of, and claims priority to and thebenefit of, U.S. Non-Provisional patent application Ser. No. 15/144,506,filed on May 2, 2016 and entitled “METHOD OF FORMING A GERMANIUMOXYNITRIDE FILM,” which is hereby incorporated by reference in itsentirety for all purposes. This application is related to U.S.Non-Provisional patent application Ser. No. 14/729,510, filed on Jun. 3,2015 and entitled “METHODS FOR SEMICONDUCTOR PASSIVATION BYNITRIDATION,” which is hereby incorporated by reference in its entiretyfor all purposes.

FIELD OF INVENTION

The present disclosure generally relates to processes for manufacturingelectronic devices. More particularly, the disclosure relates to formingfilms through atomic layer deposition (ALD). Specifically, thedisclosure discloses methods to form a charge trapping layer, such as alayer comprising germanium oxynitride, for example.

BACKGROUND OF THE DISCLOSURE

V-NAND has been identified for use in flash memory applications.Different materials have been identified for use in the V-NAND space,such as poly silicon (as a channel layer), silicon oxide (as a tunnelingoxide and blocking oxide), silicon nitride (as a charge trapping layer),and aluminum oxide (as a blocking oxide). For a material to be effectivefor V-NAND charge trapping layer (CTL), it should have a properconduction band offset (CBO), as well as the ability to generate trapswith deep energy level and reduce thermal emission. The CTL materialshould also comply with integration flow by having the followingcharacteristics: compatibility with the blocking oxide (BO); hightemperature stability; and high step coverage for an aspect ratiogreater than 1:50.

As a result, a method for forming a V-NAND device with reliableoperating capabilities is desired.

SUMMARY OF THE DISCLOSURE

In accordance with at least one embodiment of the invention, a methodfor forming a V-NAND device is disclosed. The method includes: providinga substrate for processing in a reaction chamber; performing an atomiclayer deposition cycle of a nitride onto the substrate; performing anatomic layer deposition cycle of an oxide onto the substrate; whereinthe atomic layer deposition cycle of the nitride and the atomic layerdeposition cycle of the oxide are repeated as desired in order to forman oxynitride film of a desired thickness and stoichiometry.

In accordance with at least one embodiment of the invention, a methodfor forming a V-NAND device is disclosed. The method includes: providinga substrate comprising SiO₂ for processing in a reaction chamber;performing an atomic layer deposition cycle of an oxide onto thesubstrate comprising SiO₂; performing an atomic layer deposition cycleof a nitride onto the SiO₂ substrate; wherein the atomic layerdeposition cycle of the nitride and the atomic layer deposition cycle ofthe oxide are repeated as desired in order to form an oxynitride film ofa desired thickness and stoichiometry.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the attachedfigures, the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

These and other features, aspects, and advantages of the inventiondisclosed herein are described below with reference to the drawings ofcertain embodiments, which are intended to illustrate and not to limitthe invention.

FIG. 1 illustrates a band diagram of a POR V-NAND cellin accordance withat least one embodiment of the invention.

FIG. 2 illustrates a band diagram of a POR V-NAND cell in accordancewith at least one embodiment of the invention.

FIG. 3 illustrates a process in accordance with at least one embodimentof the invention.

FIG. 4 illustrates a process in accordance with at least one embodimentof the invention.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help improve understanding ofillustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below. The describedgermanium oxynitride films may be used in other applications besidesmemory applications, such as V-NAND applications, for example. In someembodiments, the germanium oxynitride films may be used in processing ofintegrated circuits, such as sacrificial films for patterning and/orlithography applications. In addition, germanium oxynitride may be agood interface layer for high mobility SiGe/Ge channels.

V-NAND applications for memory have employed a power-off recovery (POR)cell stack. The POR cell stack has utilized a poly silicon channel, asilicon oxide (SiO₂) tunnel layer, a silicon nitride (SiN) chargetrapping layer, a silicon oxide (SiO₂) blocking layer, an aluminum oxide(Al₂O₃) high k liner, and a titanium nitride (TiN) metal gate. Duringprogramming of a memory device, electrons may be tunneled through thetunnel layer from the channel and captured in the charge trapping layer(CTL). During erasing of the memory device, the trapped charge maytunnel back to the channel; as a result, a blocking layer may ensurethat electrons will not move into the gate (during programming) or enterfrom the gate into the CTL (during erasing).

A critical property of the CTL is to have a large conduction band offset(CBO) between the CTL and the surrounding oxide layers, also known asthe tunnel layer (TL) and the blocking layer (BL). The large CBO mayprovide for good retention for a memory device. Also, the CTL may beused to generate traps, as deep traps (where the E_(t)>2 eV) may be ableto reduce thermal emission and improve retention reliability. Inaddition, even deeper traps may allow for more charging to take place.

The CTL made of silicon nitride (SiN) has shown issues with thicknesswith the general approach of scaling downwards in size. In addition, SiNhas a relatively lower electron affinity (E_(ea)), as shown in FIG. 1.The lower E_(ea) has the effect of reduced CBO and thus, worseretention. Other oxides, such as tantalum oxide (TaO_(x)) and titaniumoxide (TiO_(x)), have exhibited a large E_(ea), which can provide alarge CBO and a deep trap. However, these oxides may become crystallizedwhen grown or after exposure to a high thermal budget. The crystallizedoxide may be problematic as grain boundaries created can enhancemigration of trapped charges.

FIG. 1 illustrates a band diagram 100 of a POR V-NAND cell. The banddiagram is for a cell that includes a silicon layer 110, a silicon oxideTL 120, a silicon nitride CTL 130, a silicon oxide BL 140, an aluminumoxide high-k liner 150, and a titanium nitride metal gate 160. The banddiagram also includes a trapping energy (E_(t)) 170 and an electronaffinity (E_(ea)) 180. The E_(ea) of silicon nitride 180 isapproximately 2.1 eV.

FIG. 2 illustrates a band diagram 200 of a POR V-NAND cell in accordancewith at least one embodiment of the invention. The band diagram is for acell that includes a silicon layer 210, a silicon oxide TL 220, agermanium oxynitride CTL 230, a silicon oxide BL 240, an aluminum oxidehigh-k liner 250, and a titanium nitride metal gate 260. The banddiagram also includes a trapping energy (E_(t)) 270 and an electronaffinity (E_(ea)) 280. The E_(ea) of germanium oxynitride 280 isapproximately 3.4 eV.

The larger E_(ea) of germanium oxynitride in comparison to siliconnitride makes it an excellent candidate for a CTL in a scaled V-NANDdevice. In addition, germanium oxynitride has good amorphous featuresafter being processed in a high thermal budget. Furthermore, thegermanium oxynitride may have the potential for low intermixing with theTL and BL after exposure to a high thermal budget. The N doping levelwill tune the trap density (exceeding 5×10¹²/cm² eV, 7.5×10¹²/cm² eV,1×10¹¹/cm² eV) and trap energy level (ranging between 1.6 and 3 eV).

FIG. 3 illustrates a process 300 in accordance with at least oneembodiment of the invention. The process 300 may be used to deposit anoxynitride film, such as germanium oxynitride, through thermal atomiclayer deposition (ALD) onto a wafer in a reaction chamber. Embodimentsof this invention may be used to form oxynitride films with desiredproperties (such as trap density) in a conformal manner, such that theymay be used in three-dimensional applications as the deposition may takeplace in a thermal manner. This may avoid issues found when performing aplasma deposition on three-dimensional structures.

The ALD process may ensure thermal stability as it may enable properstacking alignment of layers. The process 300 may include an oxide cycle310 and a nitride cycle 320. The oxide cycle 310 and the nitride cycle320 both may be repeated through cycles 330, 340, and 350 as desired inorder to develop the desired thickness and stoichiometry of theoxynitride film. The oxide cycle 310 and the nitride cycle 320 may berepeated in different ratios. For example, the ratio of the oxide cycle310 to the nitride cycle 320 may vary from about 1:10 to about 100:1.

To form the germanium oxynitride film disclosed above, the oxide cycle310 may include a germanium precursor and an oxygen precursor. Thegermanium precursor may include at least one oftetrakis(dimethylamino)germanium (TDMAGe), tetrakis(diethylamino)germanium (TDEAGe), tetrakis(ethylmetlyamino)germanium(TEMAGe), germanium ethoxide (Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above, for example. The oxygen precursor may include water(H₂O), hydrogen peroxide (H₂O₂), ozone (O₃), oxygen plasma, oxygenatoms, or oxygen radicals, for example.

In at least one embodiment of the invention, more than one of thementioned germanium precursors or more than one of the mentioned oxygenprecursors may be used in the deposition of the oxynitride film. Thereaction temperature of the germanium oxide cycle 310 may range between100° C. and 500° C., and more preferably between 100° C. and 300° C. Thereaction time of the germanium oxide cycle 310 may range between 0.1 sand 100 s, and preferably between 1 s and 60 s. The pressure, for thisand other deposition steps described herein, in a reaction chamber istypically from about 0.01 to about 20 mbar, more preferably from about 1to about 10 mbar. However, in some cases the pressure will be higher orlower than this range, as can be determined by the skilled artisan giventhe particular circumstances.

In accordance with at least one embodiment of the invention, to form agermanium oxynitride film, the oxide cycle 310 may comprise a firstpulse of TDMAGe ranging between 0.1 and 10 seconds, preferably between 1and 5 seconds. The oxide cycle 310 also may comprise a purge of excessTDMAGe ranging between 0.1 and 10 seconds, preferably between 1 and 5seconds. The oxide cycle 310 may then also comprise a second pulse ofwater for 3 seconds, and a purge of excess water for 6 seconds. Theoxide cycle 310 may take place in a Pulsar® ALD reactor or an A412 batchreactor available from ASM International N.V. of Almere, Netherlands.

To form the germanium oxynitride film disclosed above, the nitride cycle320 may include a germanium precursor and a nitrogen precursor. Theprecursor may include at least one of tetrakis(dimethylamino)germanium(TDMAGe), tetrakis (diethylamino)germanium (TDEAGe),tetrakis(ethylmetlyamino)germanium (TEMAGe), germanium ethoxide(Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above. The nitrogen precursor may include hydrazine (N₂H₄),dimethyl hydrazine, tertbutyl hydrazine, ammonia (NH₃), nitrogen plasma,nitrogen atoms, nitrogen radicals, and other variants, for example.

In at least one embodiment of the invention, more than one of thementioned germanium precursors or more than one of the mentionednitrogen precursors may be used in the deposition of the oxynitridefilm. The reaction temperature of the germanium nitride cycle 320 mayrange between 100° C. and 500° C., and more preferably between 100° C.and 300° C. The reaction time of the germanium nitride cycle 320 mayrange between 0.1 s and 100 s, and preferably between 1 s and 60 s.

In accordance with at least one embodiment of the invention, to form agermanium oxynitride film, the nitride cycle 320 may comprise a firstpulse of TDMAGe lasting 3 seconds, followed by a purge of excess TDMAGefor 4 seconds. The nitride cycle 320 may then also comprise a secondpulse of hydrazine for 3 seconds, and a purge of excess water for 6seconds. The nitride cycle 320 may take place in a Pulsar® ALD reactoror an A412 batch reactor available from ASM International N.V. ofAlmere, Netherlands. The formed germanium oxynitride film may then beused for VNAND applications or as a sacrificial layer for patterning.

FIG. 4 illustrates a process 400 in accordance with at least oneembodiment of the invention. The process 400 may be used to deposit anoxynitride film through thermal atomic layer deposition (ALD) onto awafer in a reaction chamber. The ALD process may ensure thermalstability as it may enable proper stacking alignment of layers. Theprocess 400 may include a nitride cycle 320 and an oxide cycle 310. Thenitride cycle 320 and the oxide cycle 310 both may be repeated throughcycles 330, 340, and 350 as desired in order to develop the desiredthickness and stoichiometry of the germanium oxynitride film. The oxidecycle to nitride cycle ratio may range between from 5:1 to 1:15, orpreferably from 1:1 to 1:5. The nitride cycle 320 and the oxide cycle310 may be repeated in different ratios. For example, the ratio of thenitride cycle 320 to the oxide cycle 310 may vary from about 1:10 toabout 100:1.

To form the germanium oxynitride film disclosed above, the nitride cycle320 may include a germanium precursor and a nitrogen precursor. Thegermanium precursor may include at least one oftetrakis(dimethylamino)germanium (TDMAGe), tetrakis(diethylamino)germanium (TDEAGe), tetrakis(ethylmetlyamino)germanium(TEMAGe), germanium ethoxide (Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above. The nitrogen precursor may include hydrazine (N₂H₄),dimethyl hydrazine, tertbutyl hydrazine, ammonia (NH₃), nitrogen plasma,nitrogen radicals, and other variants, for example.

In at least one embodiment of the invention, more than one of thementioned germanium precursors or more than one of the mentionednitrogen precursors may be used in the deposition of the oxynitridefilm. The reaction temperature of the nitride cycle 320 may rangebetween 100° C. and 500° C., and more preferably between 100° C. and300° C. The reaction time of the nitride cycle 320 may range between 0.1s and 100 s, and preferably between 1 s and 60 s.

In accordance with at least one embodiment of the invention, to form agermanium oxynitride film, the nitride cycle 320 may comprise a firstpulse of TDMAGe lasting 3 seconds, followed by a purge of excess TDMAGefor 4 seconds. The nitride cycle 320 may then also comprise a secondpulse of hydrazine for 3 seconds, and a purge of excess water for 6seconds. The nitride cycle 320 may take place in a Pulsar® ALD reactoravailable from ASM International N.V. of Almere, Netherlands.

To form the germanium oxynitride film disclosed above, the oxide cycle310 may include a germanium precursor and an oxygen precursor. Thegermanium precursor may include at least one of:tetrakis(dimethylamino)germanium (TDMAGe); tetrakis(diethylamino)germanium (TDEAGe); tetrakis(ethylmetlyamino)germanium(TEMAGe); germanium ethoxide (Ge(OEt)₄); germanium methoxide (Ge(OMe)₄);tetrakis(trimethylsilyl)germane; germanium tetrachloride (GeCl₄); GeOR₄,where R is an alkyl or a substituted alkyl; GeR_(x)A_(4-x), where x isan integer from 1 to 4, R is an organic ligand selected from a groupcomprising alkoxides, alkylsilyls, alkyl, substituted alkyl, oralkyamines, and A can be selected from a group comprising alkyl,substituted alkyl, alkoxides, alkylsilyls, alkyl, alkylamines, halidesor hydrogen; or variants of above, for example. The oxygen precursor mayinclude water (H₂O), hydrogen peroxide (H₂O₂), ozone (O₃), oxygenplasma, or oxygen radicals, for example.

In at least one embodiment of the invention, more than one of thementioned germanium precursors or more than one of the mentioned oxygenprecursors may be used in the deposition of the oxynitride film. Thereaction temperature of the oxide cycle 310 may range between 100° C.and 500° C., between 100° C. and 300° C., and between 200° C. and 250°C. The reaction time of the oxide cycle 310 may range between 0.1 s and100 s, and preferably between 1 s and 60 s.

In accordance with at least one embodiment of the invention, to form agermanium oxynitride film, the oxide cycle 310 may comprise a firstpulse of TDMAGe lasting between 0.1 and 10 seconds, preferably between 1and 5 seconds, followed by a purge of excess TDMAGe lasting between 0.1and 20 seconds, preferably between 1 and 5 seconds. The oxide cycle 310may then also comprise a second pulse of water ranging between 0.1 to 30seconds, preferably between 1 and 5 seconds. The oxide cycle 310 mayalso comprise a purge of excess water ranging between 0.1 to 30 seconds,preferably between 5 and 10 seconds. The oxide cycle 310 may take placein a Pulsar® ALD reactor available from ASM International N.V. ofAlmere, Netherlands.

The oxynitride film formed in accordance with embodiments of theinvention may have different properties. A nitrogen concentration of theoxynitride film may be more than about 2 at-%, more than about 5 at-%,more than about 10 at-%, or more than about 20 at-%. An oxygenconcentration of the oxynitride film may be more than about 20 at-%,more than about 30 at-%, more than about 40 at-%, or more than about 50at-%. A germanium concentration of the oxynitride film may range betweenabout 20 to about 50 at-%, or from about 30 to about 40 at-%. A nitrogento oxygen-nitrogen ratio (N/(O+N)) may range from about 5 to about 60at-%, from about 10 to about 50 at-%, or from about 20 to about 40 at-%.

In some embodiments of the invention, the oxynitride film may notcomprise substantial amounts of silicon and/or metals. In someembodiments of the invention, the germanium oxynitride film may compriseless than about 5-at % of any impurity other than hydrogen, preferablyless than about 3-at % of any impurity other than hydrogen, and morepreferably less than about 1-at % of any impurity other than hydrogen.In some embodiments of the invention, the germanium oxynitride film maycomprise a hydrogen concentration less than about 20 at-%, less thanabout 15 at-%, or less than about 10%. In some embodiments of theinvention, the oxynitride film may not be a nanolaminate film, wheredistinct and/or separate layers of oxide and nitride can be observed. Insome embodiments, the oxynitride film may be of a substantiallyhomogenous mixture. In at least one embodiment of the invention, a postthermal annealing step may be used.

The particular implementations shown and described are illustrative ofthe invention and its best mode and are not intended to otherwise limitthe scope of the aspects and implementations in any way. Indeed, for thesake of brevity, conventional manufacturing, connection, preparation,and other functional aspects of the system may not be described indetail. Furthermore, the connecting lines shown in the various figuresare intended to represent exemplary functional relationships and/orphysical couplings between the various elements. Many alternative oradditional functional relationship or physical connections may bepresent in the practical system, and/or may be absent in someembodiments.

It is to be understood that the configurations and/or approachesdescribed herein are exemplary in nature, and that these specificembodiments or examples are not to be considered in a limiting sense,because numerous variations are possible. The specific routines ormethods described herein may represent one or more of any number ofprocessing strategies. Thus, the various acts illustrated may beperformed in the sequence illustrated, in other sequences, or omitted insome cases.

The subject matter of the present disclosure includes all novel andnonobvious combinations and subcombinations of the various processes,systems, and configurations, and other features, functions, acts, and/orproperties disclosed herein, as well as any and all equivalents thereof.

We claim:
 1. A method of forming a germanium oxynitride film comprising:providing a substrate for processing in a reaction chamber; using agermanium precursor and an oxygen precursor, performing an oxide cyclefor deposing an oxide comprising germanium onto the substrate; andbefore or after the performing the oxide cycle, using a germaniumprecursor and a nitrogen precursor, performing a nitride cycle fordeposing a nitride comprising germanium onto the substrate; wherein theperforming the oxide cycle and the performing the nitride cycle arerepeated as desired in order to form the germanium oxynitride film of adesired thickness and stoichiometry, and wherein the oxygen precursorand the nitrogen precursor are different.
 2. The method of claim 1,wherein the performing the oxide cycle takes place at a temperatureranging between 100° C. and 500° C. or between 100° C. and 300° C. 3.The method of claim 1, wherein the performing the oxide cycle has aduration ranging between 0.1 s and 100 s or between 1 s and 60 s.
 4. Themethod of claim 1, wherein the performing the oxide cycle comprises:pulsing the germanium precursor; purging an excess of the germaniumprecursor; pulsing the oxygen precursor; and purging an excess of theoxygen precursor.
 5. The method of claim 1, wherein the germaniumprecursor comprises at least one of: tetrakis(dimethylamino)germanium(TDMAGe), tetrakis (diethylamino)germanium (TDEAGe),tetrakis(ethylmethylamino)germanium (TEMAGe), germanium ethoxide(Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above.
 6. The method of claim 1, wherein the oxygenprecursor comprises at least one of: water (H₂O), hydrogen peroxide(H₂O₂), ozone (O₃), oxygen plasma, or oxygen radicals.
 7. The method ofclaim 1, wherein the performing the nitride cycle takes place at atemperature ranging between 100° C. and 500° C. or between 100° C. and300° C.
 8. The method of claim 1, wherein the performing the nitridecycle has a duration ranging between 0.1 s and 100 s or between 1 s and60 s.
 9. The method of claim 1, wherein the performing the nitride cyclecomprises: pulsing the germanium precursor; purging an excess of thegermanium precursor; pulsing the nitrogen precursor; and purging anexcess of the nitrogen precursor.
 10. The method of claim 9, wherein thegermanium precursor comprises at least one of:tetrakis(dimethylamino)germanium (TDMAGe), tetrakis(diethylamino)germanium (TDEAGe), tetrakis(ethylmethylamino)germanium(TEMAGe), germanium ethoxide (Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above.
 11. The method of claim 1, wherein the nitrogenprecursor comprises at least one of: hydrazine (N₂H₄), dimethylhydrazine, tertbutyl hydrazine, ammonia (NH₃), nitrogen plasma, nitrogenradicals, or variants of above.
 12. The method of claim 1, wherein thegermanium oxynitride film is used for a VNAND application or as asacrificial layer for patterning.
 13. The method of claim 1, wherein theperforming the nitride cycle is performed before the performing theoxide cycle.
 14. A method of forming a germanium oxynitride film layerfor a V-NAND stack comprising: providing a substrate for processing in areaction chamber; performing an oxide cycle for deposing an oxide ontothe substrate, the performing the oxide cycle comprising: pulsing agermanium precursor; and pulsing an oxygen precursor; and before orafter the performing the oxide cycle, performing a nitride cycle fordeposing a nitride onto the substrate, the performing the nitride cyclecomprising: pulsing a germanium precursor; and pulsing a nitrogenprecursor; wherein the performing the oxide cycle and the performing thenitride cycle are repeated as desired in order to form the germaniumoxynitride film of a desired thickness and stoichiometry, and whereinthe oxygen precursor and the nitrogen precursor are different.
 15. Themethod of claim 14, wherein the germanium precursor comprises at leastone of: tetrakis(dimethylamino)germanium (TDMAGe), tetrakis(diethylamino)germanium (TDEAGe), tetrakis(ethylmethylamino)germanium(TEMAGe), germanium ethoxide (Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above.
 16. The method of claim 14, wherein the oxygenprecursor comprises at least one of: water (H₂O), hydrogen peroxide(H₂O₂), ozone (O₃), oxygen plasma, oxygen radicals, or variants ofabove.
 17. The method of claim 16, wherein the germanium precursorcomprises at least one of: tetrakis(dimethylamino)germanium (TDMAGe),tetrakis (diethylamino)germanium (TDEAGe),tetrakis(ethylmethylamino)germanium (TEMAGe), germanium ethoxide(Ge(OEt)₄), germanium methoxide (Ge(OMe)₄),tetrakis(trimethylsilyl)germane, germanium tetrachloride (GeCl₄), orvariants of above.
 18. The method of claim 14, wherein the nitrogenprecursor comprises at least one of: hydrazine (N₂H₄), dimethylhydrazine, tertbutyl hydrazine, ammonia (NH₃), nitrogen plasma, nitrogenradicals, or variants of above.
 19. The method of claim 14, wherein theperforming the nitride cycle is performed before the performing theoxide cycle.
 20. The method of claim 14, wherein the performing thenitride cycle is performed after the performing the oxide cycle.